Field of the Disclosure
The present disclosure relates to a display device, and more particularly, to an active layer, a thin-film transistor array substrate comprising the same, and a display device comprising the same. Although the present disclosure is suitable for a wide cope of applications, it is particularly suitable for improving device characteristics of the display device by implementing an active layer formed of carbon allotropes.
Description of the Background
With the development of multimedia, flat panel displays (FDPs) are becoming more and more important nowadays. In line with this, a variety of flat panel displays such as liquid crystal displays (LCDs), plasma display panels (PDPs), field emission displays (FEDs), organic light emitting displays (OLEDs), etc. are being put to practical use.
Display devices are addressed with either a passive-matrix addressing scheme or an active-matrix addressing scheme using thin-film transistors. In the passive-matrix addressing scheme, an anode and a cathode intersect each other and selected lines are addressed. In contrast, in the active-matrix addressing scheme, each pixel electrode is attached to a thin-film transistor and switched on or off.
For a thin-film transistor, durability and electrical reliability, which are required to ensure long lifetime, are very important, as well as the fundamental characteristics such as electron mobility and leakage current, etc. An active layer of the thin-film transistor can be one of amorphous silicon, polycrystalline silicon, and oxide semiconductor. Main advantages of amorphous silicon are a simplified deposition process and a low production cost, but it has a low electron mobility of 0.5 cm2/Vs. Oxide semiconductor has an on/off ratio of about 108 and a low leakage current, but with an electron mobility of 10 cm2/Vs, which is lower compared to polycrystalline silicon. Polycrystalline silicon has a high electron mobility of about 100 cm2/Vs, but has a lower on/off ratio compared to oxide semiconductor and it costs a lot to apply polycrystalline silicon in large-area electronics. In this regard, there is ongoing research to improve the characteristics of thin-film transistors, including electron mobility, leakage current, and on/off ratio, etc.